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1.
Pediatr Surg Int ; 37(11): 1585-1592, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34268609

RESUMEN

PURPOSE: To describe the timing of chemotherapy initiation after surgery for Wilms tumor (WT) and neuroblastoma within a dedicated children's cancer center. METHODS: A single-institution retrospective cohort study identified patients that underwent resection of unilateral WT or high-risk neuroblastoma and received adjuvant chemotherapy treatment. Adjuvant chemotherapy initiation and postoperative complications were recorded. RESULTS: Among 47 WT patients, the median time to chemotherapy initiation was 11 days [interquartile range IQR 7-14]. 3 WT patients had post-operative complications, but all preceded chemotherapy. Among 83 patients treated for high-risk neuroblastoma, the median time to chemotherapy was 11 days [IQR 9-14]. High-risk neuroblastoma patients with 30-day postoperative complications had a significantly longer time to initiation of adjuvant chemotherapy (odds ratio 1.13; p = 0.008). Many of these complications preceded and delayed the initiation of post-operative chemotherapy. No complications occurred in the group of 12 (25%) WT patients or 16 (19.3%) neuroblastoma patients who started chemotherapy ≤ 7 days after surgery. CONCLUSION: There is no association between early initiation of adjuvant chemotherapy and post-operative complications including wound healing. Early initiation of chemotherapy (≤ 7 days) is feasible in unilateral WT or high-risk neuroblastoma patients who are otherwise doing well without resulting in a preponderance of wound healing complications.


Asunto(s)
Neoplasias Renales , Neuroblastoma , Tumor de Wilms , Quimioterapia Adyuvante , Niño , Humanos , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/cirugía , Laparotomía , Neuroblastoma/tratamiento farmacológico , Neuroblastoma/cirugía , Estudios Retrospectivos , Tumor de Wilms/tratamiento farmacológico , Tumor de Wilms/cirugía
2.
J Pathol ; 230(1): 95-106, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23299523

RESUMEN

Podocytes are crucial for preventing the passage of albumin into the urine and, when lost, are associated with the development of albuminuria, renal failure and cardiovascular disease. Podocytes have limited capacity to regenerate, therefore pro-survival mechanisms are critically important. Insulin-like growth factor-II (IGF-II) is a potent survival and growth factor; however, its major function is thought to be in prenatal development, when circulating levels are high. IGF-II has only previously been reported to continue to be expressed in discrete regions of the brain into adulthood in rodents, with systemic levels being undetectable. Using conditionally immortalized human and ex vivo adult mouse cells of the glomerulus, we demonstrated the podocyte to be the major glomerular source and target of IGF-II; it signals to this cell via the IGF-I receptor via the PI3 kinase and MAPK pathways. Functionally, a reduction in IGF signalling causes podocyte cell death in vitro and glomerular disease in vivo in an aged IGF-II transgenic mouse that produces approximately 60% of IGF-II due to a lack of the P2 promoter of this gene. Collectively, this work reveals the fundamental importance of IGF-II in the mature podocyte for glomerular health across mammalian species.


Asunto(s)
Factor II del Crecimiento Similar a la Insulina/metabolismo , Podocitos/citología , Podocitos/metabolismo , Transducción de Señal/fisiología , Envejecimiento/fisiología , Animales , Línea Celular Transformada , Supervivencia Celular/fisiología , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , Factor II del Crecimiento Similar a la Insulina/genética , Glomérulos Renales/citología , Glomérulos Renales/fisiología , Células Mesangiales/citología , Células Mesangiales/metabolismo , Ratones , Ratones Transgénicos , ARN Interferente Pequeño/genética
3.
Proc Inst Mech Eng H ; 225(11): 1078-83, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22292206

RESUMEN

The kinematics of the lumbar spine have previously been described by considering the bearing of the pelvis and lower back. However earlier studies have not described an intersegmental angle measured about a single point; which is necessary for investigation into movement, posture and balance, and lower back pain and injury. This study used computed tomography (CT) scans of 16 pelves to determine the location of palpable bony landmarks, and the junction of the fifth lumbar and first sacral vertebrae within a pelvis axis system. Data were used to derive equations which express the three-dimensional location of the lumbosacral joint centre as an offset from palpable surface landmarks. The magnitude of X, Y, Z offsets was controlled using individual pelvic geometry, and robustness and repeatability of the method was assessed. Regression equations provided the location of the lumbosacral junction to within 8.2mm (+/- 3.4mm) of its true coordinate. Leave-one-out analyses calculated equation coefficients using 15 of the original pelves, with the 16th acting as a control; average errors increased by 6.7 per cent (+/- 0.1 percent). To the authors' knowledge the current method is the most accurate non-invasive means of locating the lumbosacral junction and may be useful for constructing biomechanical models.


Asunto(s)
Articulaciones/anatomía & histología , Articulaciones/fisiopatología , Antropometría , Artefactos , Fenómenos Biomecánicos , Estudios de Factibilidad , Humanos , Región Lumbosacra , Modelos Anatómicos , Movimiento (Física) , Palpación , Pelvis/anatomía & histología , Pelvis/fisiopatología , Equilibrio Postural , Análisis de Regresión , Reproducibilidad de los Resultados , Columna Vertebral/fisiopatología , Tomografía Computarizada por Rayos X/métodos
4.
Curr Med Chem ; 16(6): 667-75, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19199930

RESUMEN

It is well recognised that increased levels of high density lipoprotein (HDL) protect against atherosclerosis and correlate with improved prognosis for vascular disease associated events. While many of the atheroprotective effects of HDL are ascribed to the ability to remove cholesterol from the vasculature through the reverse cholesterol transport system, recent work has shown that HDL may be atheroprotective through its other functions, such as regulation of endothelial adhesion molecule expression, stimulation of endothelial nitric oxide synthase and inhibition of the damaging effects of oxidised low density lipoproteins. Recently, HDL has also been described to interact with circulating cells inhibiting both leukocyte and platelet activation, therefore having further systemic anti-inflammatory functions. This review summarises the studies and models used to examine the anti-inflammatory effects of HDL and details data describing the ability to inhibit leukocyte activation, contributing to the hypothesis that raised HDL is beneficial in the context of inflammation in atherosclerosis. Further, HDL modification in disease and current therapeutic strategies such as reconstituted HDL particles and apoA I mimetic peptides is discussed to provide insights to the potential applicability of raising HDL to regress cardiovascular disease.


Asunto(s)
Inflamación/metabolismo , Lipoproteínas HDL/metabolismo , Animales , Humanos , Ratones , Ratas
5.
Eur Respir J ; 33(6): 1287-94, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19196819

RESUMEN

Vascular endothelial growth factor (VEGF) is an angiogenic factor implicated in asthma severity. The objective of the present study was to determine whether VEGF single nucleotide polymorphisms (SNPs) are associated with asthma, lung function and airway responsiveness. The present authors analysed 10 SNPs in 458 white families in the Childhood Asthma Management Program (CAMP). Tests of association with asthma, lung function and airway responsiveness were performed using PBAT software (Golden Helix, Inc. Bozeman, MT, USA; available at www.goldenhelix.com). Family and population-based, revpeated measures analysis of airflow obstruction were conducted. Replication studies were performed in 412 asthmatic children and their parents from Costa Rica. Associations with asthma, lung function and airway responsiveness were observed in both cohorts. SNP rs833058 was associated with asthma in both cohorts. This SNP was also associated with increased airway responsiveness in both populations. An association of rs4711750 and its haplotype with forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) ratio in both cohorts was observed. Longitudinal analysis in CAMP confirmed an association of rs4711750 with FEV(1)/FVC decline over approximately 4.5 yrs of observation. VEGF polymorphisms are associated with childhood asthma, lung function and airway responsiveness in two populations, suggesting that VEGF polymorphisms influence asthma susceptibility, airflow obstruction and airways responsiveness.


Asunto(s)
Asma/genética , Asma/fisiopatología , Factor A de Crecimiento Endotelial Vascular/genética , Adolescente , Corticoesteroides/administración & dosificación , Corticoesteroides/uso terapéutico , Antiasmáticos/administración & dosificación , Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Pruebas de Provocación Bronquial , Niño , Costa Rica , Método Doble Ciego , Femenino , Volumen Espiratorio Forzado , Genotipo , Haplotipos , Humanos , Masculino , Nedocromil/administración & dosificación , Nedocromil/uso terapéutico , Fenotipo , Placebos , Polimorfismo de Nucleótido Simple , Análisis de Regresión , Pruebas de Función Respiratoria , Programas Informáticos , Capacidad Vital , Población Blanca/genética
6.
Ann Rheum Dis ; 68(10): 1602-8, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19528034

RESUMEN

BACKGROUND: Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystal-induced interleukin 1 beta (IL1beta) release contributes to inflammation in subcutaneous air pouch and peritoneal models of acute gout and pseudogout. However, consequences of IL1 inhibition have not been explored in more clinically relevant models of crystal-induced arthritis. OBJECTIVE: To develop a novel mouse model of acute gouty ankle arthritis and use it to assess the effects of genetic deletion of IL1 receptor type (IL1R1) and of exogenous mIL1 Trap (a high-affinity blocker of mouse IL1alpha and IL1beta) on pain, synovitis and systemic inflammatory biomarkers. METHODS: MSU crystals were injected into the mouse ankle joint and pain and ankle swelling were measured over 4 days. The effects of IL1 inhibition were determined in this model, and in the comparator models of crystal-induced peritonitis and subcutaneous air pouch inflammation. RESULTS: Both IL1R1-null mice and mice pretreated with mIL1 Trap showed reduced neutrophil influx in MSU and CPPD crystal-induced peritonitis and air pouch models (p<0.05). In the ankle joint model, both IL1R1 knockout mice and pretreatment with mIL1 Trap were associated with significant reductions in MSU crystal-induced elevations in hyperalgesia, inflammation, serum amyloid A and the levels of multiple inflammatory cytokines and chemokines (p<0.05). Additionally, it was found that administration of mIL1 Trap after MSU crystal injection reduced established hyperalgesia and ankle swelling. CONCLUSIONS: IL1 inhibition both prevented and relieved pain and ankle joint inflammation in response to intra-articular MSU crystals in mice. Results suggested that IL1 Trap has the potential to both prevent and treat gouty arthritis.


Asunto(s)
Artritis Experimental/tratamiento farmacológico , Artritis Gotosa/tratamiento farmacológico , Supresores de la Gota/uso terapéutico , Hiperalgesia/prevención & control , Proteínas Recombinantes de Fusión/uso terapéutico , Sinovitis/prevención & control , Animales , Artritis Experimental/complicaciones , Artritis Gotosa/complicaciones , Biomarcadores/metabolismo , Colchicina/uso terapéutico , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Hiperalgesia/etiología , Interleucina-1/antagonistas & inhibidores , Masculino , Ratones , Ratones Noqueados , Infiltración Neutrófila , Receptores Tipo I de Interleucina-1/deficiencia , Receptores Tipo I de Interleucina-1/genética , Transducción de Señal/fisiología , Sinovitis/etiología , Regulación hacia Arriba/efectos de los fármacos , Ácido Úrico
7.
Vet Parasitol ; 153(1-2): 24-43, 2008 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-18342449

RESUMEN

We tested the hypothesis that brown-headed cowbirds (Molothrus ater) harbor Sarcocystis neurona, the agent of equine protozoal myeloencephalitis (EPM), and act as intermediate hosts for this parasite. In summer 1999, wild caught brown-headed cowbirds were collected and necropsied to determine infection rate with Sarcocystis spp. by macroscopic inspection. Seven of 381 (1.8%) birds had grossly visible sarcocysts in leg muscles with none in breast muscles. Histopathology revealed two classes of sarcocysts in leg muscles, thin-walled and thick-walled suggesting two species. Electron microscopy showed that thick-walled cysts had characteristics of S. falcatula and thin-walled cysts had characteristics of S. neurona. Thereafter, several experiments were conducted to confirm that cowbirds had viable S. neurona that could be transmitted to an intermediate host and cause disease. Specific-pathogen-free opossums fed cowbird leg muscle that was enriched for muscle either with or without visible sarcocysts all shed high numbers of sporocysts by 4 weeks after infection, while the control opossum fed cowbird breast muscle was negative. These sporocysts were apparently of two size classes, 11.4+/-0.7 microm by 7.6+/-0.4 microm (n=25) and 12.6+/-0.6 microm by 8.0+/-0 microm (n=25). When these sporocysts were excysted and introduced into equine dermal cell tissue culture, schizogony occurred, most merozoites survived and replicated long term and merozoites sampled from the cultures with long-term growth were indistinguishable from known S. neurona isolates. A cowbird Sarcocystis isolate, Michigan Cowbird 1 (MICB1), derived from thin-walled sarcocysts from cowbirds that was passaged in SPF opossums and tissue culture went on to produce neurological disease in IFNgamma knockout mice indistinguishable from that of the positive control inoculated with S. neurona. This, together with the knowledge that S. falcatula does not cause lesions in IFNgamma knockout mice, showed that cowbird leg muscles had a Sarcocystis that fulfills the first aim of Koch's postulates to produce disease similar to S. neurona. Two molecular assays provided further support that both S. neurona and S. falcatula were present in cowbird leg muscles. In a blinded study, PCR-RFLP of RAPD-derived DNA designed to discriminate between S. neurona and S. falcatula showed that fresh sporocysts from the opossum feeding trial had both Sarcocystis species. Visible, thick-walled sarcocysts from cowbird leg muscle were positive for S. falcatula but not S. neurona; thin-walled sarcocysts typed as S. neurona. In 1999, DNA was extracted from leg muscles of 100 wild caught cowbirds and subjected to a PCR targeting an S. neurona specific sequence of the small subunit ribosomal RNA (SSU rRNA) gene. In control spiking experiments, this assay detected DNA from 10 S. neurona merozoites in 0.5g of muscle. In the 1999 experiment, 23 of 79 (29.1%) individual cowbird leg muscle samples were positive by this S. neurona-specific PCR. Finally, in June of 2000, 265 cowbird leg muscle samples were tested by histopathology for the presence of thick- and thin-walled sarcocysts. Seven percent (18/265) had only thick-walled sarcocysts, 0.8% (2/265) had only thin-walled sarcocysts and 1.9% (5/265) had both. The other half of these leg muscles when tested by PCR-RFLP of RAPD-derived DNA and SSU rRNA PCR showed a good correlation with histopathological results and the two molecular typing methods concurred; 9.8% (26/265) of cowbirds had sarcocysts in muscle, 7.9% (21/265) had S. falcatula sarcocysts, 1.1% (3/265) had S. neurona sarcocysts, and 0.8% (2/265) had both. These results show that some cowbirds have S. neurona as well as S. falcatula in their leg muscles and can act as intermediate hosts for both parasites.


Asunto(s)
Enfermedades de las Aves/parasitología , Sarcocystis/aislamiento & purificación , Sarcocistosis/veterinaria , Pájaros Cantores/parasitología , Animales , Caballos , Interacciones Huésped-Parásitos , Interferón gamma/genética , Interferón gamma/metabolismo , Ratones , Ratones Noqueados , Músculo Esquelético/parasitología , Zarigüeyas/parasitología , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Polimorfismo de Longitud del Fragmento de Restricción , Sarcocystis/genética , Sarcocistosis/parasitología , Sensibilidad y Especificidad , Piel/citología , Piel/parasitología , Organismos Libres de Patógenos Específicos
8.
Nat Commun ; 9(1): 1421, 2018 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-29650949

RESUMEN

Acute allergic symptoms are caused by allergen-induced crosslinking of allergen-specific immunoglobulin E (IgE) bound to Fc-epsilon receptors on effector cells. Desensitization with allergen-specific immunotherapy (SIT) has been used for over a century, but the dominant protective mechanism remains unclear. One consistent observation is increased allergen-specific IgG, thought to competitively block allergen binding to IgE. Here we show that the blocking potency of the IgG response to Cat-SIT is heterogeneous. Next, using two potent, pre-selected allergen-blocking monoclonal IgG antibodies against the immunodominant cat allergen Fel d 1, we demonstrate that increasing the IgG/IgE ratio reduces the allergic response in mice and in cat-allergic patients: a single dose of blocking IgG reduces clinical symptoms in response to nasal provocation (ANCOVA, p = 0.0003), with a magnitude observed at day 8 similar to that reported with years of conventional SIT. This study suggests that simply augmenting the blocking IgG/IgE ratio may reverse allergy.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Desensibilización Inmunológica/métodos , Glicoproteínas/inmunología , Hipersensibilidad/terapia , Inmunoglobulina G/farmacología , Receptores de IgE/inmunología , Adolescente , Adulto , Alérgenos/administración & dosificación , Alérgenos/inmunología , Alérgenos/aislamiento & purificación , Pelaje de Animal/química , Pelaje de Animal/inmunología , Animales , Anticuerpos Monoclonales/biosíntesis , Unión Competitiva , Gatos , Mezclas Complejas/química , Mezclas Complejas/inmunología , Modelos Animales de Enfermedad , Femenino , Glicoproteínas/administración & dosificación , Glicoproteínas/aislamiento & purificación , Humanos , Hipersensibilidad/inmunología , Hipersensibilidad/fisiopatología , Inmunoglobulina E/química , Inmunoglobulina E/inmunología , Inmunoglobulina E/metabolismo , Inmunoglobulina G/biosíntesis , Masculino , Ratones , Persona de Mediana Edad , Unión Proteica/efectos de los fármacos , Receptores de IgE/química , Receptores de IgE/metabolismo
9.
Nat Biotechnol ; 16(13): 1334-7, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9853614

RESUMEN

We describe a procedure for isolating agonists for mammalian G protein-coupled receptors of unknown function. Human formyl peptide receptor like-1 (FPRL-1) receptor, originally identified as an orphan G protein-coupled receptor related to the formyl peptide receptor (FPR1), was expressed in Saccharomyces cells designed to couple receptor activation to histidine prototrophy. Selection for histidine prototrophs among transformants obtained with a plasmid-based library encoding random peptides identified six different agonists, each of whose production yielded autocrine stimulation of the receptor expressed in yeast. A synthetic version of each peptide promoted activation of FPRL-1 expressed in human embryonic kidney (HEK293) cells, and five of the peptides exhibited significant selectivity for activation of FPRL-1 relative to FPR1. One selective peptide was tested and found to mobilize calcium in isolated human neutrophils. This demonstrates that stimulation of FPRL-1 results in neutrophil activation and suggests that the receptor functions as a component of the inflammatory response. This autocrine selection protocol may be a generally applicable method for providing pharmacological tools to evaluate the physiological roles of the growing number of mammalian orphan G protein-coupled receptors.


Asunto(s)
Receptores Inmunológicos/agonistas , Receptores de Péptidos/agonistas , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Línea Celular , Humanos , Ligandos , Datos de Secuencia Molecular , Monocitos/metabolismo , N-Formilmetionina Leucil-Fenilalanina/metabolismo , Neutrófilos/metabolismo , Péptidos/química , Péptidos/metabolismo , Receptores de Formil Péptido , Receptores Inmunológicos/metabolismo , Receptores de Péptidos/metabolismo , Proteínas Recombinantes/agonistas , Proteínas Recombinantes/metabolismo
10.
J Thromb Haemost ; 15(5): 972-982, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28267256

RESUMEN

Essentials Vessel stenosis due to large thrombus formation increases local shear 1-2 orders of magnitude. High shear at stenotic sites was exploited to trigger eptifibatide release from nanocapsules. Local delivery of eptifibatide prevented vessel occlusion without increased tail bleeding times. Local nanocapsule delivery of eptifibatide may be safer than systemic antiplatelet therapies. SUMMARY: Background Myocardial infarction and stroke remain the leading causes of mortality and morbidity. The major limitation of current antiplatelet therapy is that the effective concentrations are limited because of bleeding complications. Targeted delivery of antiplatelet drug to sites of thrombosis would overcome these limitations. Objectives Here, we have exploited a key biomechanical feature specific to thrombosis, i.e. significantly increased blood shear stress resulting from a reduction in the lumen of the vessel, to achieve site-directed delivery of the clinically used antiplatelet agent eptifibatide by using shear-sensitive phosphatidylcholine (PC)-based nanocapsules. Methods PC-based nanocapsules (2.8 × 1012 ) with high-dose encapsulated eptifibatide were introduced into microfluidic blood perfusion assays and into in vivo models of thrombosis and tail bleeding. Results Shear-triggered nanocapsule delivery of eptifibatide inhibited in vitro thrombus formation selectively under stenotic and high shear flow conditions above a shear rate of 1000 s-1 while leaving thrombus formation under physiologic shear rates unaffected. Thrombosis was effectively prevented in in vivo models of vessel wall damage. Importantly, mice infused with shear-sensitive antiplatelet nanocapsules did not show prolonged bleeding times. Conclusions Targeted delivery of eptifibatide by shear-sensitive nanocapsules offers site-specific antiplatelet potential, and may form a basis for developing more potent and safer antiplatelet drugs.


Asunto(s)
Arteriopatías Oclusivas/prevención & control , Sistemas de Liberación de Medicamentos/métodos , Fibrinolíticos/administración & dosificación , Nanocápsulas , Péptidos/administración & dosificación , Inhibidores de Agregación Plaquetaria/administración & dosificación , Agregación Plaquetaria/efectos de los fármacos , Trombosis/prevención & control , Animales , Arteriopatías Oclusivas/sangre , Arteriopatías Oclusivas/fisiopatología , Fenómenos Biomecánicos , Velocidad del Flujo Sanguíneo , Preparaciones de Acción Retardada , Modelos Animales de Enfermedad , Composición de Medicamentos , Eptifibatida , Fibrinolíticos/química , Fibrinolíticos/toxicidad , Hemorragia/inducido químicamente , Ratones Endogámicos C57BL , Péptidos/química , Péptidos/toxicidad , Fosfatidilcolinas/química , Inhibidores de Agregación Plaquetaria/química , Inhibidores de Agregación Plaquetaria/toxicidad , Flujo Sanguíneo Regional , Estrés Mecánico , Trombosis/sangre , Trombosis/fisiopatología
11.
Vet Parasitol ; 135(3-4): 223-34, 2006 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-16280197

RESUMEN

The objective of this study was to evaluate the utility of a simple, efficient, and rapid method for the isolation of Sarcocystis neurona merozoites and Besnoitia darlingi tachyzoites from cultured cells. The efficacy of this purification method was assessed by microscopy, SDS-PAGE, Western blotting, immuno-fluorescence, and three novel quantitative PCR assays. Culture medium containing host cell debris and parasites was eluted through PD-10 desalting columns. This purification method was compared to alternatives employing filtration through a cellulose filter pad or filter paper. The estimated recovery of S. neurona merozoites purified by the column method was 82% (+/-3.7) of the original merozoites with 97.5% purity. In contrast, estimated recovery of S. neurona merozoites purified by filter pad and filter paper was 40% and 30% with 76% and 83% purity, respectively. The same procedures were applied to purify B. darlingi tachyzoites from cultured cells. Of the original cultured B. darlingi tachyzoites, 94% (+/-2.5) were recovered from the PD-10 column with 96.5%, purity whereas percentage recovery of B. darlingi tachyzoites purified by filter pad and filter paper were 51% and 35% with 84% and 88% purity, respectively. All described methods maintained sterility so that purified parasites could be subsequently cultured in vitro. However, purification using a PD-10 column minimized parasite loss and the loss of viability as determined by the trypan blue dye exclusion assay, the rate of parasite production, and plaque forming efficiency in cell culture. Moreover, column-purified parasites improved the sensitivity of an immuno-fluorescent (IFA) analysis and real-time quantitative PCR assays targeted to parasite 18S ribosomal DNA and hsp70 genes. This technique appears generally applicable for purifying coccidia grown in cell cultures.


Asunto(s)
Reacción en Cadena de la Polimerasa/veterinaria , Sarcocystidae/aislamiento & purificación , Sarcocystis/aislamiento & purificación , Animales , Western Blotting/métodos , Western Blotting/veterinaria , Células Cultivadas/parasitología , Electroforesis en Gel de Poliacrilamida/métodos , Electroforesis en Gel de Poliacrilamida/veterinaria , Técnica del Anticuerpo Fluorescente/métodos , Técnica del Anticuerpo Fluorescente/veterinaria , Microscopía/métodos , Microscopía/veterinaria , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad
12.
Biochim Biophys Acta ; 946(1): 57-65, 1988 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-2974728

RESUMEN

The inactivation of sarcoplasmic reticulum ATPase by fluorescein isothiocyanate (FITC) was shown to have a hyperbolic dependence on the concentration of FITC. The results were quantitatively accounted for by a model in which the reagent first binds reversibly (Kf = 70 microM) to the ATPase and then reacts irreversibly (kmax = 0.8 and 2 min-1 in the absence and presence of 1 mM Mg2+, respectively) to form inactive enzyme. Comparison with the rate constant for the reaction of the model compound alpha-acetyllysine with FITC showed that the FITC-reactive lysyl side-chain of the ATPase is not unusually reactive, indicating that the specificity of the reaction is due to affinity labeling behavior of the reagent. This was supported by protection experiments using ATP, ADP, AdoPP[NH]P, ITP, and TNP-ATP, all of which displayed protection constants similar to their known binding constants to the active site of the ATPase. Both inorganic phosphate and orthovanadate were effective in preventing inactivation by FITC, and calcium only partially reversed the effect of these anions, implying the existence of a ternary complex such as Ca2.E.Pi. Since all ligands (ATP, ADP and Pi) which bind or react at the catalytic site protect it, only the unliganded form appears to bind and react with FITC. Addition of calcium to the MgATP complex of the ATPase caused an increase in the FITC inactivation rate, implying that during turnover there is a larger fraction of unliganded enzyme present, i.e., substrate binding is weaker (Ks is larger). Protection was also observed with fluorescein and two related dyes, eosin and erythrosin. Like FITC, the isothiocyanates of these dyes were effective inactivators. In separate experiments, these two dyes were shown to promote photoinactivation of the ATPase. ATP exerted a protective effect with a concentration dependence consistent with high-affinity active-site binding.


Asunto(s)
Marcadores de Afinidad/metabolismo , ATPasas Transportadoras de Calcio/metabolismo , Retículo Sarcoplasmático/enzimología , Animales , Sitios de Unión , Fluoresceína-5-Isotiocianato , Fluoresceínas , Matemática , Fosfatos/farmacología , Conejos , Tiocianatos , Vanadatos/farmacología
13.
Biochim Biophys Acta ; 904(2): 227-38, 1987 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-2959323

RESUMEN

The triazine dye, Reactive Red 120, was found to bind tightly (Kd = 30) nM) and with low stoichiometry to sarcoplasmic reticulum membranes. Our finding that this high-affinity binding caused noncompetitive inhibition of the Ca2+-ATPase indicates that the dye-binding site is distinct from both the active site and putative regulatory site. Detergent solubilization (monomerization) of the Ca2+-ATPase caused a 25-fold decrease in affinity for Reactive Red 120, while causing no decrease in affinity toward another dye, Reactive Blue 2. For the Reactive-Red-120-inhibited enzyme, the level of steady-state enzyme phosphorylation by ATP was not significantly different from that exhibited by the control Ca2+-ATPase. The rate of dephosphorylation in the presence and absence of ADP, however, was markedly decreased by the presence of the inhibitor. Distance measurements by fluorescence energy transfer from the active (FITC-reactive) site to the Reactive Red 120 site gave a value of 59 A. Similar experiments yielded an average distance of 35 A between the latter site and the tryptophan residues, most of which are postulated by the 'sequence model' (MacLennan et al. (1985) Nature 316, 696-700) to be located in a transmembrane domain.


Asunto(s)
ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Colorantes/farmacología , Músculos/enzimología , Retículo Sarcoplasmático/enzimología , Triazinas , Animales , Detergentes/farmacología , Cinética , L-Lactato Deshidrogenasa/metabolismo , Fosforilación , Piruvato Quinasa/metabolismo , Conejos
14.
Bone Marrow Transplant ; 35(8): 775-9, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15765115

RESUMEN

The aims of this study were to establish the nutritional status of children pre-BMT and to determine whether predictive methods of assessing nutritional status and resting energy expenditure (REE) are accurate in this population. We analysed the body cell mass (BCM) (n=26) and REE (n=24) in children undergoing BMT. BCM was adjusted for height (BCM/HT(p)) and expressed as a Z score to represent nutritional status. To determine whether body mass index (BMI) was indicative of nutritional status in children undergoing BMT, BMI Z scores were compared to the reference method of BCM/HT(p) Z scores. Schofield predictive equations of basal metabolic rate (BMR) were compared to measured REE to evaluate the accuracy of the predictive equations. The mean BCM/HT(p) Z score for the subject population was -1.09+/-1.28. There was no significant relationship between BCM/HT(p) Z score and BMI Z score (r=0.34; P>0.05); however there was minimal difference between measured REE and predicted BMR (bias=-11+/-149 kcal/day). The results of this study demonstrate that children undergoing BMT may have suboptimal nutritional status and that BMI is not an accurate indication of nutritional status in this population. However, Schofield equations were found to be suitable for representing REE in children pre-BMT.


Asunto(s)
Anemia/terapia , Trasplante de Médula Ósea/métodos , Metabolismo Energético , Leucemia/terapia , Estado Nutricional , Adolescente , Factores de Edad , Metabolismo Basal , Composición Corporal , Estatura , Índice de Masa Corporal , Peso Corporal , Niño , Ingestión de Energía , Femenino , Humanos , Masculino , Estudios Retrospectivos
15.
Vet Parasitol ; 127(1): 3-8, 2005 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-15619368

RESUMEN

Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable S. neurona from the blood of immunocompetent horses. Horses used in this study received orally administered S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 28 days, followed by 1000/day for 56 days. On day 98 of the study, six yearling colts were selected for attempted culture of S. neurona from blood, two testing positive, two testing suspect and two testing negative for antibodies against S. neurona on day 84 of the study. Two 10 ml tubes with EDTA were filled from each horse by jugular venipuncture and the plasma fraction rich in mononuclear cells was pipetted onto confluent equine dermal cell cultures. The cultures were monitored weekly for parasite growth for 12 weeks. Merozoites grown from cultures were harvested and tested using S. neurona-specific PCR with RFLP to confirm species identity. PCR products were sequenced and compared to known strains of S. neurona. After 38 days of in vitro incubation, one cell culture from a horse testing positive for antibodies against S. neurona was positive for parasite growth while the five remaining cultures remained negative for parasite growth for all 12 weeks. The Sarcocystis isolate recovered from cell culture was confirmed to be S. neurona by PCR with RFLP. Gene sequence analysis revealed that the isolate was identical to the challenge strain SN-37R and differed from two known strains UCD1 and MIH1. To our knowledge this is the first report of parasitemia with S. neurona in an immunocompetent horse.


Asunto(s)
Enfermedades de los Caballos/parasitología , Parasitemia/veterinaria , Sarcocystis/aislamiento & purificación , Sarcocistosis/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/líquido cefalorraquídeo , Secuencia de Bases , ADN Protozoario/química , ADN Protozoario/genética , Enfermedades de los Caballos/sangre , Caballos , Masculino , Datos de Secuencia Molecular , Parasitemia/sangre , Parasitemia/inmunología , Parasitemia/parasitología , Reacción en Cadena de la Polimerasa/veterinaria , Polimorfismo de Longitud del Fragmento de Restricción , Sarcocystis/genética , Sarcocystis/inmunología , Sarcocistosis/sangre , Sarcocistosis/inmunología , Sarcocistosis/parasitología , Alineación de Secuencia , Análisis de Secuencia de ADN
16.
J Sci Med Sport ; 8(3): 305-13, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16248471

RESUMEN

This project aimed to determine 1) whether creatine (Cr) supplementation affects cardiovascular structure and function and 2) to examine its effect on aerobic power. Eighteen males undertook aerobic testing on a cycle ergometer and echocardiographic assessment of the heart. The experimental group (N = 9) ingested 20g x day(-1) of Cr for seven days followed by l0g x day(-1) for a further 21 days. The control group (N = 9) followed an identical protocol ingesting a placebo for the same period. Assessment was performed pre-, mid- (seven days) and post-testing (28 days). A MANOVA with repeated measures was used to test for group differences before and after supplementation. The Cr group demonstrated a significant increase in body mass for the pre-mid (1.0 +/- 0.6 kg) and the pre-post (1.5 +/- 0.7 kg) testing occasions. Submaximal VO2 decreased significantly from the pre-mid and pre-post testing occasions by between 4.8% to 11.4% with Cr supplementation at workloads of 75 W and 150 W. Other oxygen consumption measures and exercise time to exhaustion, for the Cr group, showed decreasing trends that approached significance. Additionally, there was a significant pre-post decrease in maximum heart rate of 3.7%. There were no changes in any of the echocardiographic or blood pressure measures for either group. The present results suggest short term Cr supplementation has no detectable negative effect on cardiac structure or function. Additionally, Cr ingestion improves submaximal cycling efficiency. These results suggest that the increase in efficiency may be related to peripheral factors such an increase in muscle phosphocreatine, rather than central changes.


Asunto(s)
Creatina/administración & dosificación , Suplementos Dietéticos , Ecocardiografía , Consumo de Oxígeno/efectos de los fármacos , Adulto , Análisis de Varianza , Índice de Masa Corporal , Circulación Coronaria , Ergometría , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Resistencia Física/efectos de los fármacos
17.
Indian J Cancer ; 52(2): 225-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26853414

RESUMEN

BACKGROUND: Survivors of childhood cancer are at increased risk for several cardiometabolic complications. Obesity/overweight and metabolic syndrome have been widely reported in Western literature, but data from India are lacking. AIMS: To perform an objective assessment of nutritional status in a cohort of childhood cancer survivors (CCSs) and to find risk factors for extremes in nutritional status. SETTINGS AND DESIGN: The study was a retrospective chart review of CCSs who attended the late effects clinic of a referral pediatric oncology center over the period of 1 year. MATERIALS AND METHODS: An objective assessment of nutritional status was done, and results were analyzed in two groups: Adult survivors (present age <18 years) and child and adolescent survivors (CASs) (<18 years). The data were then analyzed for possible risk factors. RESULTS: Six hundred and forty-eight survivors were included in the study; of these, 471 were <18 years at follow-up, and 177 were 18 years or older. The prevalence of obesity, overweight, normal, and undernutrition was 2.6%, 10.8%, 62.7%, and 28.8% (CASs) and 0%, 8.5%, 62.7%, and 28.8% (adult survivors), respectively. Factors predictive of overweight/obesity were an initial diagnosis of acute lymphoblastic leukemia, or brain tumor and follow-up duration of >20 years or current age >30 years in adult survivors. CONCLUSIONS: The prevalence of obesity/overweight is lower in our cohort when compared to Western literature. It remains to be clarified whether this reflects the underlying undernutrition in our country, or whether our cohort of survivors is indeed distinct from their Western counterparts. Comparison with age/sex-matched normal controls and baseline parameters would yield more meaningful results.


Asunto(s)
Neoplasias/epidemiología , Estado Nutricional , Obesidad/epidemiología , Sobrepeso/epidemiología , Adolescente , Niño , Preescolar , Femenino , Humanos , India , Lactante , Masculino , Neoplasias/complicaciones , Neoplasias/patología , Obesidad/complicaciones , Obesidad/patología , Sobrepeso/complicaciones , Sobrepeso/patología , Pediatría , Pobreza , Factores de Riesgo
18.
Oncogene ; 34(5): 558-67, 2015 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-24488013

RESUMEN

Diffuse infiltrative invasion is a major cause for the dismal prognosis of glioblastoma multiforme (GBM), but the underlying mechanisms remain incompletely understood. Using human glioma stem cells (GSCs) that recapitulate the invasive propensity of primary GBM, we find that EphA2 critically regulates GBM invasion in vivo. EphA2 was expressed in all seven GSC lines examined, and overexpression of EphA2 enhanced intracranial invasion. The effects required Akt-mediated phosphorylation of EphA2 on serine 897. In vitro the Akt-EphA2 signaling axis is maintained in the absence of ephrin-A ligands and is disrupted upon ligand stimulation. To test whether ephrin-As in tumor microenvironment can regulate GSC invasion, the newly established Efna1;Efna3;Efna4 triple knockout mice (TKO) were used in an ex vivo brain slice invasion assay. We observed significantly increased GSC invasion through the brain slices of TKO mice relative to wild-type (WT) littermates. Mechanistically EphA2 knockdown suppressed stem cell properties of GSCs, causing diminished self-renewal, reduced stem marker expression and decreased tumorigenicity. In a subset of GSCs, the reduced stem cell properties were associated with lower Sox2 expression. Overexpression of EphA2 promoted stem cell properties in a kinase-independent manner and increased Sox2 expression. Disruption of Akt-EphA2 cross-talk attenuated stem cell marker expression and neurosphere formation while having minimal effects on tumorigenesis. Taken together, the results show that EphA2 endows invasiveness of GSCs in vivo in cooperation with Akt and regulates glioma stem cell properties.


Asunto(s)
Neoplasias Encefálicas/genética , Carcinogénesis/genética , Glioblastoma/genética , Proteína Oncogénica v-akt/genética , Receptor EphA2/genética , Animales , Neoplasias Encefálicas/patología , Regulación Neoplásica de la Expresión Génica , Glioblastoma/patología , Humanos , Ratones , Ratones Noqueados , Invasividad Neoplásica/genética , Células Madre Neoplásicas/patología , Proteína Oncogénica v-akt/metabolismo , Fosforilación/genética , Factores de Transcripción SOXB1/genética , Transducción de Señal/genética
19.
FEBS Lett ; 263(1): 175-7, 1990 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-2158904

RESUMEN

The gamma-P adduct of ATP with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (ATP-EDC) was synthesized and incubated with the Ca-ATPase of sarcoplasmic reticulum with the result that time-dependent complete loss of the enzyme's activity occurred. The inactivation required calcium and magnesium while ATP had a protective effect. ATP-EDC incubation with the NaK-ATPase and HK-ATPase produced partial (greater than 50%) inactivation, but had no effect on myosin S1, pyruvate kinase and hexokinase, suggesting that this ATP analog is a specific inactivator of the so-called 'P-type' ATPases.


Asunto(s)
Adenosina Trifosfatasas/antagonistas & inhibidores , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Carbodiimidas/farmacología , Etildimetilaminopropil Carbodiimida/farmacología , Retículo Sarcoplasmático/enzimología , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Animales , Perros , ATPasa Intercambiadora de Hidrógeno-Potásio , Riñón/enzimología , Cinética , Músculo Liso/enzimología , Músculos/enzimología , Conejos , Estómago/enzimología , Porcinos
20.
FEBS Lett ; 187(1): 131-4, 1985 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-3160607

RESUMEN

Sarcoplasmic reticulum CaATPase hydrolysis of high concentrations of ATP was studied in the presence of ADP. The results obtained were best described as noncompetitive inhibition; added product lowered the Vmax but did not affect the slopes of Eadie-Hofstee plots. At these concentrations (0.5-5 mM), ATP is known to act as both a substrate and as an activator of turnover. The inability of ATP to overcome ADP inhibition suggests that activating ATP binds to an allosteric regulatory site rather than to the phosphorylated active site.


Asunto(s)
Adenosina Trifosfato/metabolismo , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Retículo Sarcoplasmático/enzimología , Adenosina Difosfato/metabolismo , Animales , Sitios de Unión , Cinética , Matemática , Conejos
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